.NET compare two lists for equivalence using a predicate sort key.

IEnumerableExtensions.cs

using System;
using System.Collections.Generic;
using System.Linq;

namespace Extensions
{
    public static class IEnumerableExtensions
    {
        // e.g. bool sameList = list1.Equals(list2, entity => entity.Id)

        public static bool Equals<T, TKey>(this IEnumerable<T> source, IEnumerable<T> listToCompare, Func<T, TKey> predicate) where T : class
        {
            return ((null == source || null == listToCompare) ? source == listToCompare : ((source.Equals(listToCompare)) | (source.OrderBy(predicate).SequenceEqual(listToCompare.OrderBy(predicate)))));
        }
    }
}